The present invention relates to cable management for optical fiber termination systems. Specifically, the invention relates to terminations, and cable guides and troughs for managing the fiber optic cables extending to the terminations in frames, modules, blocks, and other fixtures.
In telecommunications industry, the demand for added capacity is growing rapidly. This demand is being met in part by the increasing use and density of fiber optic transmission equipment. Even though fiber optic equipment permits higher levels of transmission in the same or smaller footprint than traditional copper transmission equipment, the demand requires even higher levels of fiber density. This has led to the development of high-density fiber handling equipment.
Examples of this type of equipment are found in U.S. Pat. Nos. 5,497,444, 5,717,810 and 5,758,003. These patents disclose systems of high-density fiber distribution frames and high-density fiber termination blocks (FTBs) which are mounted to the frames. Because of the large number of optical fibers passing into and out of the FTBs, the frame and blocks have a variety of structures to organize and manage the fibers. Some structures are used to aid the fibers entering the back of the frame and FTBs. The FTBs include slideable modules to allow selective access to the densely packed terminations. Further structures are provided for managing the cables leaving the FTBs on the front. The front cables are typically cross-connect cables for connecting to other FTBs or other equipment. These cross-connect cables tend to be used in a much more dynamic fashion, whereas the rear cables tend to be much more static once initial installation is complete.
In an example fiber optic termination and cross-connection usage, there is often a pairing of FTBs, one connected to the outside plant fiber cable, and the other connected to the array of fibers linked to telecommunications devices throughout a facility. These FTBs would typically be mounted adjacent to one another in a fiber distribution frame, or mounted in neighboring distribution frames, in a facility switching area. Cross-connect cables are used to optically link the termination of an outside plant fiber in the outside plant FTB to the termination of a facility device fiber in the facility FTB. The cross-connect cable would be lead from the termination at one FTB through a series of cable guides, troughs and/or rings in the frame holding that FTB, through known structures for securing the slack in the cross connect cables, into the cable guides, troughs and/or rings in the frame holding the second FTB and end at the termination in the second FTB.
As new termination blocks and frames have been developed allowing ever higher levels of density of fiber, a need for better cross-connect cable management has been recognized. Concerns have arisen with respect to cables from terminations higher in the FTB hanging on top of and interfering with the movement of cables from terminations lower in the FTB. Also, cross-connect cables from FTBs mounted higher in the frame have longer lengths of cross-connect cables hanging in the vertical cable channels leading the cable out of the frame. The weight of these vertical lengths can exacerbate the interference problems caused by overhanging cables. These concerns can become magnified when coupled with the sliding modules incorporated into a high-density fiber distribution frame such as shown in the above-referenced patents.
The sliding of the modules to permit better access to the high density of fiber terminations inside a FTB requires that the cables attached to the terminations have some combination of slack and movement. When a cross-connect cable is attached to an FTB in a frame and the cable is led out of the FTB, through the cable guides, troughs and/or rings and into the vertical cable channel, much of the slack is pulled out of the cable by the weight of the cable hanging vertically in the channel. Therefore, some movement of the cables is necessary. But the cables attached to lower mounted modules in the FTB tend to be overlaid by the cables attached to higher mounted modules in the same FTB. The movement of the lower cables necessary to allow the modules to slide is hindered by the interference of the higher cables, making sliding of the modules difficult.
For the sliding modules themselves, cable pull can be an issue. Denser systems are desired, where the effects of cable pull are minimized. As the distances moved by the modules are increased, the problems of cable pull are increased as each module and the cables connected thereto are moved a greater distance relative to the FTB.
Further development in fiber termination systems is desired.
An aspect of this invention relates to a fixture for managing cables attached to adaptor modules. The adaptor modules slide relative to the fixture in a non-perpendicular direction angled relative to a longitudinal axis of the adaptor.
Another aspect of this invention relates to a fiber distribution frame with a plurality of fiber termination blocks with sliding cable adaptor modules mounted on the frame. The modules are mounted to the blocks to move in a non-perpendicular angled direction to manage cross-connect cables extending from the blocks. The modules may be configured in two groups which slide in an angled direction from opposite sides of the blocks. Cable guides may be mounted in corresponding relationship with the sliding adaptor modules adjacent to a front of the blocks. Cable slack storage is provided adjacent to a rear of the blocks.
A variety of advantages of the invention will be set forth in part in the detailed description that follows and in part will be apparent from the description, or may be learned by practicing the invention. It is understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the invention as claimed.